EEWeb Pulse - Volume 35

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PULSE

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Issue 35 February 28, 2012

Jim Hargrove Analytic Systems

Electrical Engineering Community

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TA B L E O F C O N T E N T S TABLE OF CONTENTS

4

Jim Hargrove Analytic Systems Interview with Jim hargrove - President

10

More Reliability for Railway Low Voltage Power Requirements

BY JIM HARGROVE

Analytic Systems’ president outlines the company’s innovations in creating reliable power sources for Illinois’ railway system.

13 15

Featured Products Arduino for Mere M0rtals - Part 2

BY ROBERT BERGER WITH RELIABLE EMBEDDED SYSTEMS

How Arduino’s open-source products and licensing allow for a thriving creative community with a burgeoning internet following.

Increasing Home Efficiency with High Brightness LEDs

20

BY TAMARA SCHMITZ WITH INTERSIL

Why High Brightness LEDs (HBLEDs) are the most efficient lighting option and how they are spurring a revolution in the home lighting industry.

RTZ - Return to Zero Comic

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3

INTERVIEW

Analytic Systems

How did you get into electronics/engineering and when did you start?

My dad, Lloyd Hargrove, was a brilliant electrical engineer, working on such historically significant projects as the Avro Arrow while working at Computing Devices of Canada. His last position was Chief Civilian Engineer for the Underwater Acoustics division of the Canadian Navy (also known as Anti-Submarine Warfare). When he moved to the west coast and founded his own company in 1976, he wanted the ASW initials, and coined the name Analytic Systems Ware, which we still use today.

moved to British Columbia with my family and went to The University of British Columbia to study electrical engineering. I graduated with a BASC in 1981.

Can you tell us about your journey to becoming the President of Analytic Systems?

I started working for my dad at the original Analytic Systems as

Jim Hargrove - President

There was never a question or even a discussion about what I would become. It was understood and accepted that I would also become an electrical engineer. After graduating from Grade 13 in Ottawa, Ontario as an Ontario Scholar, I

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FEATURED INTERVIEW

Jim Hargrove

INTERVIEW

Will you tell us about founding CompuNav Systems in 1983 and its process toward becoming the largest North American manufacturer of Marine Autopilots?

Analytic Systems was in deep financial trouble, and my dad had an immigrant investor in Analytic Systems who didn’t see much chance to recover his investment.

I had worked for Analytic Systems without pay for more than a year (while newly married), and when the investor—Wilfriede Ortlepp— suggested that we take the autopilot design and found a new company to build and sell them as repayment, I agreed. I couldn’t see a better option at that time, so we founded CompuNav Systems in 1983. It was while working with Mr. Ortlepp that I learned the value of faith in one’s self, persistence and focus. It took years, but CompuNav became quite successful.

What have been some influences that have helped you get to where you are today?

There have been a number of people who have been instrumental in shaping who I am today. Although my partnership in CompuNav ended badly, I learned a great deal about business from Mr. Ortlepp.

He was a very good businessman

and the lessons I learned from ten years of working with him definitely helped me develop Analytic Systems. Harold Copping, the former general manager of Teleflex Canada stepped in a number of times and made suggestions to improve Analytic Systems. I always listened to him and it always made a positive difference. When I knew

One of the main reasons we remain versatile and responsive is by giving ownership of a project or design to a small team, and then staying out of the way.

Micromanaging is stifling to creativity, so we try very hard to avoid it.

I was leaving CompuNav and going back to Analytic Systems as president, I took the Management Skills for Advanced Technology (MSAT) program at Simon Fraser University. This program touched on all the areas that would be covered in much greater depth in an MBA,

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and gave me a good foundation for effectively leading Analytic Systems.

Do you have any tricks up your sleeve?

Not so much a trick, but advice.

When we founded CompuNav, we drew up a formal partnership agreement, but with no money, I couldn’t afford the lawyer fees anymore, and the agreement was never signed. This came back to haunt me when our partnership began to fail ten years later. There was no shotgun clause, or anything I could use to force dissolution of the partnership. I finally agreed to a buyout for about 10 cents on the dollar. So If you have the opportunity to go into business my advice is to go for it, but do what it takes to do the due diligence at the beginning when everyone is enthusiastic and agreeable. Then if things take a wrong turn down the road, you have some recourse.

After CompuNav, when I decided to come back to Analytic Systems, we did everything right. We founded a new company Analytic Systems Ware (1993) Ltd. It bought the assets and intellectual property from the original company. We drew up proper agreements and I made sure my dad had independent legal advice to ensure that everything was clear and legal. The last thing I needed was for this to create a division in the family. As it turns out, we worked together amazingly well from 1993 right up to his death in 2009, some 16 years later.

What has been your favorite project?

I still think the autopilots were some

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FEATURED INTERVIEW

an engineering student in about 1979, joining full time in 1981 after graduating from UBC. Back then, interest rates were above 20 percent and my dad got into serious financial difficulty. The project I was working on at the time was a new microprocessor-based automatic pilot for steering boats.

INTERVIEW from the 30,000 foot level. I find that I get too involved when I sit in on design meetings, and I can skew the team’s focus. I do talk to individual designers and have them show me what they are working on, whether it’s hardware, mechanical, firmware or testing. Everyone likes to show me their designs.

After returning to Analytic Systems, I think the best projects I worked on were our sine wave inverters—all of which are still in production today.

How has the company changed since you took over control in 1993?

When I took over Analytic Systems in 1993, it was still an R&D company that would design anything for anyone.

Projects that were in progress at the time were an electronic calf feeder system, automated message-on-hold system (for InfoChip Communications) and more.

There had been something like 340 unique R&D projects done by the company between 1976 and 1993.

But the company had a library of power conversion designs, and I had learned how to build and sell a line of products in my years at CompuNav, so we finished the R&D jobs that were open, and then converted the company to design and manufacture its own products.

The most interesting OEM project I was directly involved with was the Modern Burner Unit or MBU—a new field cooking system for the US army. These new cook stoves were microprocessor controlled and needed electricity to function.

Two electrical sources were a battery pack rechargeable from a Humvee and a power supply that ran from a genset. We had orignially designed and built the battery pack, but later we had the opportunity to also design and build an improved version of the power supply. When we got the first order for power supplies in 2002, it doubled the size of the company overnight. We have continued to build on that success.

Do you have any note-worthy engineering experiences?

I have never really sought any special recognition for my work.

I’ve been too busy just trying to make ends meet. The success of the business has been enough recognition.

Do you continue to maintain an active role in product development? If so, how?

I tend to keep an eye on engineering

How does Analytic Systems remain one of the most versatile and responsive designers in the power conversion industry?

One of the main reasons we remain versatile and responsive is by giving ownership of a project or design to a small team, and then staying out of the way. Micromanaging is stifling to creativity, so we try very hard to avoid it. We engage in a lot of training, both internally and outof-house to stay on top of current

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trends in design. Plus, we have been lucky enough to attract a great team of designers and we make sure they get exposure to our customers by accompanying our sales people to trade shows.

By owning our own CNC Machining facility (Metal Action Machining), we have a great deal of added flexibility when it comes to ruggedized packaging—particularly with respect to our military work.

Can you tell us about some of the new technologies Analytic Systems is working on in the military, converters, power supply and battery areas of research?

We don’t work on batteries, but rather on ways to recharge them.

And to explain that, let’s first go back to 1976. My dad designed one of the first DC to DC voltage converters for use on fishing boats. Back then, commercial fishing boats needed 32 volts DC to start their engines. At the time, there was really no good way to take 32 volts down to 12 volts.

One of my dad’s customers was COMDEV Marine—an offshoot of the original company, Computing Devices of Canada. They asked him to design a DC to DC voltage converter that would take 32 volts in, and produce 12 volts out within a 150-watt single side band radio without using a battery. He did so, long before the PWM controllers we all use today were available. We still make a variation of that product today, called the VTC300.

We later found out that people were connecting the converters to 12-volt batteries. Of course, what would happen in these instances

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FEATURED INTERVIEW

of my best work as an engineer. The ComDev Marine 2000, the ComNav Marine 2001, 1001, 1420 and Sitex SP70 were all my designs or were under my direction. I just went sport fishing for a day out of Honolulu and the boat we were on had a ComNav 1420. The captain was blown away to have the inventor on his boat.

INTERVIEW

We actually started building battery chargers very close to the beginning of the technology, so we have a long history of building them. What we’re doing today is adapting and changing, adding features like the three-stage charging and absorption modes.

We are now going very deeply into microprocessor and DSP-based controls. So what we’re working on right now is a generic battery charger design that incorporates all of those things, as well as the corresponding PC interface, so that the whole thing will be configurable from a laptop or other device with a USB port. The goal for us is to take our battery charger technology to the next level.

We are also currently working on projects that incorporate the following attributes: • Digital control for both PWM and charging algorithm control.

• We’re also looking at better convection cooling as a research

project with Simon Fraser University.

• High-temperature materials used in combination with advanced cooling techniques (like Al substrate PCB, direct bonding to cold plates or heat sinks).

• The use of Silicone Carbide (SiC) based components in our circuits.

I really believe that we have to get better about “Made in North America.” Whether it’s better design for manufacture or better techniques for manufacture, we need to return to our roots.

• Rugged designs for high-vibration environments.

• The use of planar and/or integrated magnetics.

• Designs with special-machined features that increase the compactness level and power conversion density in terms of W/ liter or W/Kg. • The use of switch mode architectures that are suitable for wide input voltage range applications; units are accepting a

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wide input voltage range (1:20) like SOLARMAX 10 to 200V input.

• The use of cutting edge techniques to reduce EMC(radiated and conducted noise) and increase product immunity levels in very noisy electromagnetic environments.

In terms of EMC, do you have the resources to do in-house testing?

Yes, we do our EMC compliance testing on-site; we want to know ourselves that we already passed, and have all of the facilities inhouse to do so. It’s very nice because when we didn’t have the resources we would have to travel to the certification labs, which are a plane ride away. There’s nothing worse than going all the way there and finding out that we failed. We got really lucky because of our relationship with BCIT. They had a full-blown state-of-the-art EMC chamber at their facility, sitting in pieces and not being used. We were able to pick it up for next to nothing.

Can you tell us more about your machine shop? Is it its own business?

Yes, it’s an independent business called Metal Action Machining—an aerospace CNC shop. Last year we got both Metal Action and Analytic Systems approved to ISO9001-2008.

We found out though that Metal Action’s aerospace customers really wanted us to move from ISO9001 to AS9100—the aerospace quality standard. We just successfully completed our final audit and both Analytic Systems and Metal Action are now certified to AS9100. We find that there is a very great synergy

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FEATURED INTERVIEW

was that the converter would run at the intermittent current rating and overheat, resulting in failure of the converter. So we ended up learning how to adapt the DC to DC voltage converter to become a battery charger. Essentially, you put an isolation diode on the output and adjust the voltage a little bit to get the correct voltage on the output side of the diode, and you turn the current limit down to the continuous rating so you no longer have an intermittent rating—rather just a continuous. So the same voltage converter that had a 25-amp continuous, 35-amp peak output became a 25-amp, two-stage battery charger.

INTERVIEW and

Is your business open to custom product designs for customers?

We have a huge OEM division, which right now probably consists of more than half of the work we do.

For example, I can tell you that we are currently the official supplier to AAI Corp. (a Division of Textron Systems) of ground crew station power for the Shadow unmanned aerial system (UAS) program. It is a very big project for us right now.

We’re working with Raytheon on an alternative vehicle mounted charger for the US Army and USMC. We also have Argon ST (a Division of Boeing Corp), Lockheed Martin and Syracuse Research Corporation as customers of ours.

Our business model is that if we think there is a good business case at the end for manufacturing, we typically underwrite a lot of the R&D. So we’ll

work at or about cost, because our profit model comes from selling the products, and we’ve been very successful at that to the point where our standard product line, although viable, now needs updating.

Can you tell us about the MPPT Solar Charge Controller?

We licensed the patented MPPT Solar Charger technology from the British Columbia Institute of Technology (BCIT). The concept was great, but when it came to getting the design approved by CSA and UL, there were a number of deficiencies. We also determined that the original design didn’t have a high enough input voltage range.

We have worked very hard on resolving the deficiencies, finishing the project and getting it to market.

We should finally be there in a few months. This technology will be well suited to connect any power source with a VI curve, such as a solar panel to a storage battery bank like small water power or wind power.

What can we expect to see from Analytic Systems in the near future?

We have been very successful working on OEM projects in the past few years, mostly Military COTS or full MIL-SPEC, but we feel very strongly that we need to get back to updating and expanding our standard product line. While I can’t go into specifics, we expect a steady stream of new product announcements over the next couple of years.

What challenges do you foresee in our industry?

I really believe that we have to get better about “Made in North America.” Whether it’s better design for manufacture or better techniques for manufacture, we need to return to our roots. As we move more and more into an all-electric economy, the need for all types of power conversion is going to continue to grow. It’s a very exciting place to be right now! ■

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between CNC machining electronics manufacturing.

Technology You Can Trust

Ultra Low Power Digital Optocouplers in Industrial Communication Interfaces 90% less power than standard optocouplers 40% lower power than alternative opto-isolators • Ultra low power • High temperature and supply voltage range • High noise immunity (35 kV/µs dynamic and static common mode rejection) • Certified for safe insulation (up to 1140 Vpeak continuous working voltage)

To request a free evaluation board go to: Avago Technologies new generation optocouplers, ACPL-x6xL series and www.avagotech.com/optocouplers ACNW261L, offer significant power efficiency improvements for industrial communication interfaces. With 35 years of experience in digital optocoupler design, Avago delivers quality you can count on.

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ACPL-M61L/064L/W61L/K64L

Controller

Transceiver

Bus Line

Key Features

PROJECT

FEATURED PROJECT

MORE R R

eliability for ailway Low Voltage Power Requirements

By Jim Hargrove

M

any manufacturers of power conversion equipment for rail or transit depend on standard commercial components. This white paper explores the increasingly strong demand for more rugged and therefore more reliable power conversion products to meet the demands of the rail/transit industry by reducing their downtime for maintenance to a minimum. It also studies the challenges posed by Analytic Systems’ initial customer as to how they have improved their error reporting capability for their power units.

Illinois Commuter Rail Operator, Metra, was experiencing unacceptable downtime related to their low voltage power supply used to power all low voltage electrical on board (lights, etc.). A 480V 3 phase input UPS combining both an AC to DC power supply and a separate battery charger that provides

regulated 32VDC power to the low voltage power systems. In case of a failure of the 480VAC feed, the low voltage systems are maintained from the batteries.

In addition to inadequate reliability, Metra’s previous product lacked field serviceability and adequate

monitoring/data collection capability. Their supplier preferred having the units sent back to their factory (in France) without sending a representative to Metra to explore options and develop innovative solutions. When Analytic Systems was offered the opportunity, they went to

Figure 1

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PROJECT 41V/60A max

480Vac (line voltage)

Charger

(max50V/60A)

LVPS

SD Card Log

(max50V/60A) 32V default

Digital Control Diagnostic

COM

Port (RS232)

Port (RS232)

Computer

Computer

(diagnostic)

LED Display (V, A, alarms)

(on board)

Figure 2

Figure 3

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Loads

Key Metra’s criteria were lower cost of ownership and greater power system reliability. A key design limitation was that the recommended charging algorithm to maximize the performance of Metra’s NiCad batteries required that the battery/battery charger circuit be isolated from the load. A DC Power supply feeds a regulated 32VDC to the loads. A separate Battery charger provides 38.5VDC to the battery string.

As there is no direct connection between the battery and the loads in normal operation the charger can make use of power saving /charging technologies. In the event of a failure of either the 480VAC power feed or the AC/DC power supply the transfer switch will trigger DC power to the loads from the battery.

Modular construction was used as a design basis to be easier to build (reduced cost) and easier to repair (lower down time) with back up inventory to be shipped on 24 hour notice if needed. The Charger and AC/DC power supply modules are identical in design and construction with their functionality determined by the on board microprocessor.

Analytic Systems’ BCA-PWS480-36

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FEATURED PROJECT

NiCd Battery

Analytic systems power supply (inside area)

Metra’s facility in Chicago to review the situation and gain a better understanding of the project’s requirements. They had not built a 480vdc, 3ph unit before, but were confident that it was well within their scope of operation and high on their list of new product evolution. This project gave them an opportunity to grow in a relatively new market. They had the know-how and the engineering resources available just at the right time.

PROJECT

The modular construction combined with microprocessor control will allow Analytic Systems to use the basic design for future custom opportunities and the freedom to do more than just charge the current battery. Should Metra, or any other user, wish to make a change to a new battery chemistry/ technology in the future, the unit’s computer control enables it to be firmware modified to charge many different battery chemistries and be applicable to other high voltage applications (military, industrial, etc.).

Here are a few features of the Analytic Systems’ BCA-PWS480-36 low voltage power system: • -40C to +70oC operating temperature. The most rugged components were specified to provide the greatest reliability in a wide temperature, high vibration under rail environment.

All life time limited components such as electrolytic capacitors are long life (>70,000hrs at 105C with ripple) and wide temperature storage range (-40C to +105C). High voltage semiconductors are derated in applied voltage to minimize failure due to the ‘Single Event Burnout’ (SEB) effect.

• Event data logging with SD card data storage allowing data recovery even in cases of catastrophic module failure.

LED display allows system diagnostics without a laptop

computer or other interface devices.

FEATURED PROJECT

was designed as a custom dedicated unit to meet Metra’s strict specifications.

• Convection cooled. The unit was designed with superior, proprietary thermal transfer management systems designed for superior reliability with the assistance of a local university that specializes in thermal management studies.

• The model is 93% efficient and has a 0.9-0.95 power factor (passive solution).

• It starts up and operates on its own without a separate auxiliary supply with default safe values for its output voltage setting.

This allows basic function (powering the load from AC line) even with the digital PCB failed. A bypass diode on the power supply output allows powering of the load with the contactor failed or not closed due to digital PCB or software failure. If one of the converters fails then the contactors can be operated such that the other can power the load and maintain some level of charge in the batteries. The converters also would run on single phase at half power if allowed by the digital PCB software.

Analytic Systems design and product development capabilities allowed them to deliver a product in the form of the BCA-PWS480-36 Power System which addressed all the concerns that Metra had with its incumbent system at a significant savings in purchase, operating and maintenance costs while providing a number of firsts for Analytic Systems:

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Figure 4

• First 3ph, 480V power supply; • First field upgradable firmware (customer will not need to ship the 70+ lb unit back if they wanted additional features or bug repairs), which allows the upgrades to be sent over the internet; • First SD card logging system; • Error reporting will allow the user to diagnose the unit without a need for a laptop or other special hardware (saving costs); • LED display powered by automatic software control (shows all error codes); • Communication protocols for monitoring and data logging of operating parameters; • First forward converter active clamp with 4 MOSFETs in series. ■

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F E AT U R E D P R O D U C T S VIA Technologies, Inc, a leading innovator of power efficient x86 processor platforms, announced the latest VIA COMe-8X90 module, featuring a 1.2GHz VIA NanoTM X2 E-Series dual core processor and the VIA VX900H media system processor (MSP). The ruggedized VIA COMe-8X90 module targets industrial PC and large OEM customers focused on dynamic application segments, including medical, advanced gaming, industrial automation and digital signage. Measuring 95mm x 125mm, COM Express is an industry standard embedded form factor developed and maintained by the PICMG (PCI Industrial Computer Manufacturers Group). COM Express modules integrate core CPU, chipset and memory on the module, providing support for extensive connectivity options, including USB, audio, video, and Ethernet, through board-to-board connectors to an I/O carrier board. The modular approach allows for short time-to market, application-specific customization, simplified development, high stability and long life cycles.

For more information, please click here.

Fastest 16-bit DAC at 1.5 GSPS Continuing to push the limits of data converter performance, Texas Instruments Incorporated introduced the industry’s fastest 16-bit digitalto-analog converter (DAC). The quad DAC34SH84 is 50-percent faster and uses 50-percent less power than the closest 16-bit DAC alternative, clocking in at 1.5 GSPS and consuming just 362 mW per channel. The DAC34SH84 provides an easy, pin-compatible upgrade from the 1.25GSPS DAC34H84 for customers wanting to maximize speed in 3G, LTE, GSM and WiMAX wireless base stations and repeaters; microwave point-to-point radio; software defined radio; and waveform generation systems. For more information, please click here.

Low Power “Wolverine” microcontroller Imagine a device worn on your finger that allows intuitive, touch-free interaction with the digital world. Imagine a solar panel the size of a microcontroller that enables environmental intelligence in any building.

Imagine integrating carbon monoxide sensing, thermostat control and biometric security capabilities to a smoke detector without increasing its size. This smarter, greener, battery-free world is fast becoming a reality with the world’s lowest-power microcontroller platform from Texas Instruments Incorporated (TI) (NASDAQ: TXN). Codenamed “Wolverine” for its aggressive power-saving technology, this ultra-lowpower MSP430 microcontroller platform offers at least 50 percent less power consumption than any other microcontroller in the industry (360 nA real-time clock mode and less than 100 uA/MHz active power consumption). The first devices based on this platform will be the MSP430FR58xx microcontroller series with expected availability in June 2012. For more information, please click here.

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FEATURED PRODUCTS

64-bit Computer-on-Module

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Robert Berger

Embedded Software Specialist

Arduino

for mere m0rtals - PART 2 Disclaimer The views, opinions, positions or strategies expressed by the author and those providing comments are theirs alone, and do not necessarily reflect the views, opinions, positions or strategies of anybody else.

Why bother?

Be pragmatic. I was not excited about the hardware specs from above, but being a pragmatic person, I looked a bit into the numbers. I would estimate that more than 150,000 boards have been sold in the meantime, so let us have a look at what Google tells us about Arduino compared to similar prototyping systems (See Figure 1).

Just give it a try yourself here.

Why are so many people interested in Arduinos?

Are they all Open-Source enthusiasts?

Open Source Software In 1991 some guy in Finland decided to start a project which we all know today as ”GNU/Linux” [1]. It is certainly a milestone in the open-source software movement and

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the kernel is licensed under the GNU General Public License, version 2 [2].

The Arduino software is also open-source. The source code for the Java environment is released under the GPL, version 2 and the C/C++ microcontroller libraries are under the LGPL [4] [3]. It would always be better to push your code mainline, but the Arduino software license model basically means that you can use the microcontroller libraries without giving your code back to the community. But as soon as you modify either the Java environment or the microcontroller libraries, you have to make your modifications available to the community.

Open-Source Hardware So far so good with open-source software. It’s well established and there are many licenses you can choose from [5]. What’s more ”uncommon” is open hardware.

Open-source hardware shares many of the principles and approaches of free and open-source software.

People should be able to study the hardware to understand how it works, make changes to it, and share those changes. To facilitate this, all of the original design

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TECHNICAL ARTICLE 1.00

parallax

1.00

mbed

Google Trends

0.02

Search Volume Index

TECHNICAL ARTICLE

arduino

D C E

4.00

A

B

2.00

0 2004

2005

2006

2007

2008

2009

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News Volume Reference

0 Figure 1: Google trends arduino, Parallax, mbed

files (Eagle CAD) for the Arduino hardware are released.

These files are licensed under a Creative Commons Attribution Share-Alike license [6], which allows for both personal and commercial derivative works, as long as you credit Arduino and release their designs under the same license. [3] The Arduino hardware license model basically means that if you build your own board based on Arduino, you have to give credit to the Arduino group. And if you make any modifications, your new design must be licensed under the same or a similar Creative Commons license [6].

Another example which takes the concept of open-source hardware a step further and uses Arduinos for motor control are the 3D Printers from http://www.makerbot. com/. They can even build themselves and are a step toward what’s called ”personal manufacturing [7].”

If you want to get involved in open hardware and want funding or support for a project, you might want to have a look at Kickstarter [8].

How to make money with Open-Source?

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People from the Free Software Foundation [9] will tell you that it’s not about “free” as in no cost, but “free” as in freedom. The idea comes from a philosophical point of view, but we have to realize that in the real world we also need some money.

As opposed to what happens with ”traditional” hardware shops, a low-cost manufacturer could legally take your designs and create something cheaper to compete against you. If your hardware is not open-source, this might also happen through reverse engineering, the difference being that in the case of open-source hardware, it’s actually encouraged to copy your hardware. Like this, you might avoid many costly lawsuits, and it also forces you to stay a step ahead of your competition and create better and higher quality products to stay in business.

Having the Arduino brand and taking the board out of the equation for a moment, many companies will still approach you for your system design and software expertise, and being a community leader you are always the first to know which direction the community moves.

Being first and having the expertise are valuable assets that can be offered as professional consulting services.

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TECHNICAL ARTICLE TECHNICAL ARTICLE

Thriving Community The absolute best feature of Arduino is it’s thriving community. A Google search for Arduino returns about 13,300,000 results in 0.24 seconds, which shows that the community is very much alive and kicking!

Check some of the projects to see what I mean: [10], [11], [12], [13], [14], [15], [16], [17], [18].

What follows are some pictures of projects that use Arduino: from a simple Arduino kit and test setup to more fancy stuff like a helicopter that automatically avoids obstacles, as well as a 3D printer.

Figure 4: ArduIMU Quadcopter + Arduino [19]

Figure 2: Arduino UNO + parts

Figure 5: RepRap v2 Mendel + Arduino [20]

Arduino & RepRap – Creating Wealth by Giving it Away video.

Stay tuned for some hands-on stuff in the next part of this series!

References [1] ”Linux History on Wikipedia” http://en.wikipedia.org/ wiki/History_of_Linux [2] ”GNU General Public License, version 2” http://www. gnu.org/licenses/gpl-2.0.html [3] ”Arduino Frequently Asked Questions” http://www. arduino.cc/en/Main/FAQ [4] ”GNU Lesser General Public License” http://www. gnu.org/licenses/lgpl.html Figure 3: Arduino UNO in action

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[5] ”Open Source Licenses” http://www.opensource.org/ licenses/index.html

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17

TECHNICAL ARTICLE [7] ”Personal manufacturing is getting close to ’tipping point’ – what is Australia doing about it?” http:// edgeiscore.com/personal-manufacturing-is-gettingclose-to-ti# [8] ”Kickstarter” http://www.kickstarter.com/discover/ categories/open hardware [9] ”Free Software Foundation” http://www.fsf.org/

[16] ”Minibloq” http://blog.minibloq.org/ [17] ”Digikey – Arduino”http://search.digikey.com/ scripts/DkSearch/dksus.dll?x=0&y=0&lang=en&site= us&KeyWords=Arduino [18] ”Adafruit – Arduino” http://www.adafruit.com/ category/17 [19] ”DIY Drones – ArduIMU Quadcopter” http:// diydrones.com/profiles/blogs/arduimu-quadcopter

[10] ”Arduino blog” http://arduino.cc/blog/

[20] ”RepRap Mendel 3D printer” http://reprap.org/wiki/ Mendel

[11] ”Hackaday – Arduino” category/arduino-hacks/

About the Author

http://hackaday.com/

[12] ”Makezine – Arduino” http://blog.makezine.com/ archive/category/arduino [13] ”Instructables – Arduino” http://www.instructables. com/technology/arduino/ [14] ”Hifiduino” http://hifiduino.wordpress.com/ [15] ”Toolduino” http://nootropicdesign.com/toolduino/ index.html

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Robert Berger is a highly respected and experienced embedded real-time expert and CEO of Reliable Embedded Systems, a leading embedded training consultancy. Robert consults and trains people all over the globe on a mission to help them create better embedded software. He specializes in training and consulting for embedded systems, from small real-time systems to multi-core embedded Linux. ■

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[6] ”Creative Commons Attribution-ShareAlike Licenses” http://creativecommons.org/licenses/by-sa/2.5/

Get the Datasheet and Order Samples http://www.intersil.com

6A Digital Synchronous Step-Down DC/DC Converter with Auto Compensation ZL2101

Features

The ZL2101 is a 6A digital converter with auto compensation and integrated power management that combines an integrated synchronous step-down DC/DC converter with key power management functions in a small package, resulting in a flexible and integrated solution.

• Integrated MOSFET Switches

The ZL2101 can provide an output voltage from 0.54V to 5.5V (with margin) from an input voltage between 4.5V and 14V. Internal low rDS(ON) synchronous power MOSFETs enable the ZL2101 to deliver continuous loads up to 6A with high efficiency.

An internal Schottky bootstrap diode reduces discrete component count. The ZL2101 also supports phase spreading to reduce system input capacitance.

• Snapshot™ Parametric Capture

Power management features such as digital soft-start delay and ramp, sequencing, tracking, and margining can be configured by simple pin-strapping or through an on-chip serial port. The ZL2101 uses the PMBus™ protocol for communication with a host controller and the Digital-DC bus for interoperability between other Zilker Labs devices.

• Test and Measurement Equipment

• 6A Continuous Output Current • ±1% Output Voltage Accuracy • Auto Compensation • I2C/SMBus Interface, PMBus Compatible • Internal Non-Volatile Memory (NVM)

Applications • Telecom, Networking, Storage equipment • Industrial Control Equipment • 5V and 12V Distributed Power Systems

Related Literature • AN2010 “Thermal and Layout Guidelines for Digital-DC™ Products” • AN2033 “Zilker Labs PMBus Command Set - DDC Products” • AN2035 “Compensation Using CompZL™”

100 VOUT = 3.3V

EFFICIENCY (%)

90 80 70 60 50 40 0.0

VIN = 12V fSW = 200kHz L = 6µH 1.0

2.0

3.0

4.0

5.0

6.0

IOUT (A)

FIGURE 1. ZL2101 EFFICIENCY

January 23, 2012 FN7730.0

Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2012 All Rights Reserved. All other trademarks mentioned are the property of their respective owners.

Tamara Schmitz

Senior Principal Applications Engineer And Global Training Coordinator

Increasing Home Efficiency with

High Brightness LEDs T

here are a multitude of reasons to outfit homes with High Brightness Light Emitting Diodes (HBLEDs): they save significant amounts of energy, they are safer for the environment because they contain no mercury (as fluorescent does), they reduce maintenance costs because their lifespan is the longest, and they also increase safety because they don’t instantaneously fail; instead, they gradually degrade.

High power LEDs are driven at high current on the order of 350–1000 mA. With the latest technology, they can produce 40 to 80 lumens per watt and come in 1-3 watt packages. The major manufacturers, according to the U.S. Department of Energy website, are Cree, Philips and Osram.

LED technology has been improving steadily since the turn of the millennium. Their light output (in lumens/watt) surpassed all other sources of light about two years ago. This, combined with the large energy savings, is spurring a revolution in home lighting.

After presenting a comparison of HBLEDs with the major and popular light sources, incandescent and fluorescent, we present an example home application circuit.

Comparison of Light Sources Well-informed customers will seek out ways of using HBLEDs as often as possible. In a table of comparison (Figure 1), it is clear that the brightest solutions are HBLED.

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Let’s take a closer look at the table.

The efficacy of the light source is similar to the efficiency. How much of the energy going into the bulb is turned into light as opposed to heat?

Higher numbers are preferred, and HBLED provides them. If the driving current fluctuates, incandescents are the most likely to show a change in color tint.

The major benefit for both fluorescent and HBLED over incandescent is in lifespan. This is one of the main reasons that incandescent bulbs are being phased out of circulation in many countries. It follows that HBLEDs can pull ahead of fluorescents in popularity because they are solidstate (made of silicon and not fragile), very small and contain no hazardous chemicals.

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TECHNICAL ARTICLE INCANDESCENT FLUORESCENT

CFL

EFFICACY

22%

0.7-2.6%

8-15%

9%

COLOR TINT VS CURRENT

Little

Change

No

No

Focuses

Reflector

Reflector

Reflector

LIFESPAN (HOURS)

50k

1k-2k

30k

10k

VIBRATION/SHOCK

Solid-state

Fragile

Fragile

Fragile

DIMENSION

Very small

Bulky

Bulky

Bulky

MERCURY

No

No

Yes

Yes

FAILURE MODE

Decay

Burn Out

Burn Out

Burn Out

DRIVER CIRCUIT

Power Supply

AC

Ballast

Ballast

LIGHT ANGLE

Figure 1: Comparison of Different Light Sources

HBLED Lighting Design Goals To switch to HBLEDs, customers are demanding high quality. They want designs with a power factor of at least 90 and an efficiency of 80 percent or better. In DC applications, the maximum input voltage tops out around 40 volts.

In AC applications, there might be 120V or 240V (maximum 277V) inputs. The HBLEDs must be driven by pulse-width modulators running at frequencies in excess of 120Hz to minimize any visible distraction.

Sometimes that frequency needs to be variable. In addition to these design constraints, both isolated and non-isolated designs are used, depending on the engineer and the application. A final complexity that might be considered, when necessary, is a dimming circuit.

As you can see, there isn’t one blanket solution. There are also considerations within the design to take into consideration. Each solution is specifically defined

by LED quantity and the current running through them. Adjustments

must also be made for variations in magnetic components as well as the chosen power components and output capacitors.

Application Circuit The price of HBLEDs is approximately $1 to $2. Since they are used in strings for each solution, this frees the converter from being the design cost constraint.

The first controller to present is the ISL6721. It is a single-ended pulse width modulating current mode controller. Its peak current mode control effectively handles power transients and provides inherent over-current protection. It has been configured as an actual T8 replacement circuit (replacing the traditional ballast circuit in a fluorescent lighting set-up) at a major contact manufacturer. The ISL6721 can also be configured as an incandescent light replacement.

A non-isolated flyback solution is currently lighting a mall in Asia.

That solution uses 10 HBLEDs and has a 10W output with an efficiency of 82 percent.

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To truly be competitive in the home market, an HBLED lighting solution has to offer a dimmable option.

A clever circuit can accomplish this. Remember that the LEDs are driven by pulse width modulating controllers. This means that they are not “on” constantly. The amount that they are powered is controlled and can be variable. Coincidentally, this is accomplished by the “controller.”

Figure 2 shows the complete schematic for a down lighting solution of a 6-LED adapter with dimming. The heart of the design (besides the HBLEDs, of course) is the ISL6745A controller. The components at the top right create a sepic controller driving the string of six HBLEDs. The surrounding amplifiers provide current regulation, short-circuit protection and over-voltage protection. On the bottom left you’ll find the ACdimming circuit. The dimmer amplifier output is filtered before serving as the reference node on the current regulator to feed back into the loop.

The bias voltage, VDD, of the ISL6745A can range from 6.5V to 20V. The outputs are 12V, 1A lowside FED drivers to drive a low side FETs (like Q1 in this design), the gate of a high voltage driver IC or a gate drive transformer.

The ISL6745A is the most popular HBLED driver in Intersil’s portfolio.

In addition to the uses highlighted in Figure 1, it has adjustable switching frequency, adjustable soft start, over-temperature protection, and precision adjustable “deadtime.” It is offered in a space-saving MSOP10 package. As a hallmark of its flexibility, the ISL6745A can work

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HBLED

TECHNICAL ARTICLE TECHNICAL ARTICLE

Figure 2: 6-LED Adapter with Dimming for Down Lighting

isolated or non-isolated as well as dimmable or non-dimmable.

Conclusion HBLEDs are the greenest alternative for consumer lighting, and technology has advanced enough to make them viable. Replacement solutions are available to replace both incandescent and fluorescent designs. Save power, increase lifespan, improve safety and increase reliability—use HBLEDs.

Tamara holds a BSEE and MSEE in electrical engineering and a PhD in RF CMOS Circuit Design from Stanford University. From 1997 until 2002 she was a lecturer in electrical engineering at Stanford; from 2002 until 2007, she served as assistant professor of electrical engineering at San Jose State University. â–

About the Author Tamara Schmitz is a Senior Principal Applications Engineer and Global Technical Training Coordinator at Intersil Corporation, where she has been employed since 2007.

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